package com.test.shiyan4;

public class Mymath {
    public static final double PI = 3.14;

    public static double ymj(double r){
        return PI * r * r;
    }
    public static double yzttj(double r,double h){
        return h * PI *r * r/3;
    }

    public static int fbng(int n){
        if (n==1 || n==2){
            return 1;
        }
        if (n>2) {
            return fbng(n-1) + fbng(n-2);
        }
        return -1;
    }
}
